JPS5943646B2 - shaft coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft coupling using a coil spring as a rotation transmission elastic element.

Several shaft joints using coil springs as transmission elements have been commercialized because they have a relatively large effect of adjusting and buffering misalignment between shaft centers.

FIG. 1 shows an example of such a shaft coupling.

In this shaft joint, a plurality of spring holes 2 are provided in each of a pair of facing bubs 1.

A coil spring 3 is inserted into the spring hole 2 so as to span between the bubbles 1.

The torque is from the one-force bub 1 to the other force bub 1 to the coil spring 3
transmitted via.

Adjustment and damping of the misalignment between the axes is achieved by deforming the coil spring 3 in the direction of force transverse to the spring axis.

Although the shaft coupling shown in FIG. 1 has a simple structure, it has the following problems.

That is, since the coil spring 3 is loosely fitted into the spring hole 2, there is play between both the bubs 1, and the rotation angle accuracy is poor.

In particular, the inner circumferential surface of the spring hole 2 expands during use due to impact and abrasion caused by the coil spring 3.

This further reduces the rotational angle accuracy and reduces fatigue failure of the coil spring 3.

This invention is an improvement on the shaft joint shown in FIG. 1, which has the advantage of a simple structure.

This invention has a relatively simple structure and aims to provide a shaft joint with no play between the bub and the coil spring.

The shaft coupling of the present invention each has a flange at one end of a cylindrical portion, and includes a first bub and a second bub to which a transmission shaft is connected, and a plurality of spring holes are provided in the flange along the circumferential direction. A first bub and a second bub are arranged so that the flanges face each other with an interval therebetween, and a coil is inserted into the spring hole so as to span the flanges.

The coil spring or spring clamp is compressed by a bolt in the direction of the spring axial force, and the outer diameter of the spring is expanded to tightly fit into the spring hole.

The shaft joint configured as described above utilizes the characteristic that when the coil spring is compressed, the outer diameter when compressed becomes larger than the outer diameter when no load is applied, in proportion to the amount of deflection.

In other words, when assembling the coil spring into the spring hole of the drive shaft side and driven shaft side bubbles, the size allows the coil spring to be inserted freely into the hole without any load, and by compressing the coil spring after one centering is completed, a large surface The outer periphery of the coil spring is elastically crimped.

During rotation, the coil elastically deforms in a direction perpendicular to the spring axis in proportion to the transmitted torque, transmitting torque and providing a buffering effect.

There is no play between the bub and the elastic element, and even if some wear occurs on the large surface, the elastic force that increases the outer diameter of the coil spring will always maintain a play-free state, providing a cushioning effect.
Performs axial center adjustment.

As mentioned above, one of the features of the present invention is that the coil spring can always maintain a state without play, and the structure allows torque to be transmitted directly from the drive shaft side bubble to the driven shaft side bubble using only the coil spring. design, and torque does not act directly on joint parts such as reamer bolts.
The advantage is that it is possible to construct a shaft joint with absolutely no play.

As shaft couplings with absolutely no play, commercially available small bellows type couplings include couplings in which the drive shaft side/X bulb, bellows, driven shaft side bubble and all transmission components are joined by welding. This method is limited to very small products, and for normal size products, assembly work is extremely difficult and it is almost impossible to apply this method.

In addition to the above-mentioned features, the present invention has the following advantages: The coil spring used in the present invention generally has the same capacity because the coil spring assembly structure and spring specifications can be freely selected from a wide range depending on the assembly conditions. It is much more compact than typical commercially available couplings, such as gear couplings and flange-type flexible joints, and is naturally cheaper to manufacture.

In addition, regarding maintenance during operation, in the present invention, there is no play in the connection between the bub and the transmission element, and the action of the transmission element is elastic deformation, so greasing is not necessary in principle. It is.

Of course, since it is constructed with metal contact, it is natural that the lifespan will be longer if it is lubricated.

Next, preferred embodiments of the present invention will be described.

FIGS. 2 and 3 are a side sectional view and a partially sectional front view, respectively, showing an example of the shaft coupling of the present invention.

As shown in these drawings, the shaft coupling is mainly composed of a drive shaft side bubble 4, a driven shaft side bubble 9, a holding cover 16, and a coil spring 25.

The drive shaft side bub 4 has a flange 6 at one end of a cylindrical portion 5, and the flange 6 is provided with three spring holes 7 passing through it along the axial direction.

The spring hole 7 is finished with high accuracy using a reamer.

Furthermore, a bolt hole 8 is provided between adjacent spring holes 7, which is larger in diameter than the reamer bolt 28 and has a gap corresponding to the allowable eccentricity.

The driven shaft side bub 9 includes a flange 11 at one end of a cylindrical portion 10.

The flange 11 is provided with spring holes 12 and reamed bolt holes 13 at positions corresponding to the spring holes 7 and bolt holes 8 of the flange 6 of the drive shaft side bub 4, respectively.

Although the spring hole 12 is reamed, the flange 11
has not penetrated.

The holding cover 16 is provided with an opening 17 through which the cylindrical portion 5 of the drive shaft knob 4 passes and a recess 18 that accommodates the flange 6 of the drive shaft knob 4.

Further, a non-penetrating spring hole 19 and a reamer bolt hole 20 are formed at positions corresponding to the spring hole 7 and the reamer bolt hole 8 of the flange 6 of the drive shaft side bub 4, respectively.

An 0-IJ song groove 1 is cut on the circumferential surface of the opening 17.

A gap a is provided between the opening 17 and the cylindrical portion 5 of the drive shaft bub 4 for axial center adjustment.

The coil spring 25 is a rectangular spring whose outer peripheral surface is polished to high precision.

The outer diameter of the coil spring 25 is the same as that of the spring hole 7 when no load is applied.
The dimensions are such that they play 12°19 and form an interference fit when compressed.

The bubs 4 and 9 are arranged with flanges 6.11 facing each other, and the spring holes 7 and 12 have coil springs 2.
5 is inserted.

Then, the holding cover 16 is fixed to the driven shaft side 9 by a reamer bolt 28 with the coil spring 25 inserted into the spring hole 19 of the holding cover 16.

At this time, the coil spring 25 is in a compressed state.

When the coil spring 25 is compressed, its outer diameter slightly expands, and it becomes an interference fit with the spring holes 7, 12 degrees 19.

Table 1 shows an example of actually measured expansion of the outer diameter of the coil spring 25 due to compression.

To show the fit between the spring holes 7, 12, 19 and the coil spring 25 in concrete numerical values, when using the coil spring 25 with G in the above table, the fit between the spring holes 7, 12, and 9 is 0.05~ 0
．． It has a clearance of 08M and can be inserted freely.

Further, during compression, there is an elastic wire allowance of 0.10 to 0.13, and there is no play between the coil spring 25 and the spring holes 7, 12, and 19.

Note that the space within the holding cover 16 is sufficiently large so that the flange 6 of the drive shaft side hub 4 can freely move when the axis of the shaft joint in operation is adjusted.

Also, the O-ring 3 attached to the O-ring groove 21
0 prevents water from entering the holding cover 16 from the outside.

Here, the operation of the shaft joint configured as described above will be explained.

First, since this is a flexible joint, three types of axial center adjustment actions, namely eccentricity adjustment action, oblique angle adjustment action, and axial displacement adjustment action, will be explained.

1. Eccentricity Adjustment Operation FIG. 4 is an explanatory diagram of the eccentricity adjustment operation. When eccentricity δ occurs, as shown in the figure, the coil spring 25 deforms into a shape in which the spring axis is curved, thereby adjusting the eccentricity.

In this case, the maximum allowable amount of eccentricity is the gap a in the figure.

The maximum eccentricity of the limit plate is determined by the size of b and 1/2 of the diameter difference between the outer diameter of the reamer bolt 28 in FIG. 2 and the bolt hole 8 of the flange 6 of the drive shaft side hub 4. is determined.

2. Oblique Angle Adjustment FIG. 5 is an explanatory diagram of the oblique angle adjustment. As shown in the figure, the oblique angle θ is adjusted by changing the eccentricity δ1 and the axial lengths 1, , t2.

δ1 is adjusted by the same effect as the eccentricity adjustment effect of item 1, tl is adjusted by compressive deformation, and 4 is adjusted by elongated deformation.

The maximum allowable oblique angle is the angle at which 11 or 0 becomes 0, that is, the angle at which the flange 6 of the drive shaft side hub 4 contacts the flange 11 of the driven shaft side hub 9 or the holding cover 16.

Of course, geometrically, due to oblique intersection, when the gap a becomes O and there is contact, the size of the oblique angle is limited by that angle, but
Generally, even if the angle becomes 11 or 4, a does not become 0.

3. Adjustment of axial displacement FIG. 6 is an explanatory diagram of the adjustment of axial displacement. Displacement e is adjusted by compression, and displacement 4 is adjusted by elastic deformation of extension.

However, if the shaft joint is assembled from the beginning in the state shown in Figure 6, elastic deformation due to compression and expansion as shown in Figure 6 will not occur, and both 11 and 4 will be compressed uniformly. In this state, the outer periphery of the coil spring 25 is crimped into each of the spring holes 4, 12, and 19, and this state is set as a neutral position.
Vibration displacement in the axial direction during rotation is adjusted by the compression/stretching action described at the beginning.

As mentioned above, we have explained the deviation on both axes by dividing it into three types of components: eccentricity, oblique angle, and axial displacement, but in reality, the three elements are mixed, so in that case, The allowable amount is the gap a, b mentioned above.

It is limited by c and d, and is naturally smaller than the maximum allowable amount of each component.

Table 2 shows the main specifications of a representative example of the shaft coupling series that is actually manufactured using the structure shown in FIG.

The rotational torque is transmitted from the drive shaft side bubble 4 to the driven shaft side bubble 9 and the holding cover 16 via the coil spring 25.

During this time, the rotation is transmitted while the elastic force due to the elastic deformation of the coil spring 25 in the direction perpendicular to the spring axis and the rotational torque always maintain a balance.

Therefore, the shock torque from either the load side or the drive side is buffered, and torsional vibrations are leveled out.

The relative rotation angle between the drive shaft side bubble 4 and the driven shaft side bubble 9 is
The angle at which the outer periphery of the reamer bolt 28 contacts the bolt hole 8 provided in the flange 6 of the drive shaft side bub 4 is
This is the maximum allowable buffer rotation angle.

Torque beyond that is transmitted from the drive shaft side bubble 4 to the driven shaft side bubble 9 and the holding cover 16 via the reamer bolt 28, and in this case, the drive shaft side bubble 4 becomes rigid in the rotation direction.

For the embodiment shown in FIG. 2, the coil spring 25 is compressed when assembled, but in the resting state:
The thrust force by the coil spring 25 does not act on either the drive shaft side bubble 4 or the driven shaft side bubble 9 at all.

When vibration accompanied by axial displacement occurs during rotation, a thrust proportional to the amount of displacement acts due to the compression of the coil spring 25, and this thrust force causes
Axial vibrations decay early.

Next, other embodiments will be described.

In the following drawings, members that are substantially the same as those shown in the existing drawings are designated by the same reference numerals as in those drawings.

In FIG. 7, the reamer bolt 28 in FIG. 2 is provided through the bolt hole 8 of the flange 6 of the drive shaft side bub 4, whereas the bolt hole is provided in the drive shaft side bub 31. figure,
The flange 34 of the driven shaft side bub 33 is further enlarged on the outer periphery, and the holding cover 36 is similarly enlarged, so that they can be reamed directly to each other.
It has a structure in which it is fastened with bolts 38.

Although the outer diameter is larger than the embodiment shown in FIG. 2, it is possible to mount a large number of coil springs 25.

FIG. 7 shows an embodiment in which 24 coil springs 25 are incorporated.

However, in this case, in the embodiment shown in FIG. 2, the reamer bolt 28 and the bolt hole 8 contact each other, transmitting torque without going through the coil spring 25, and preventing the coil spring 25 from acting against excessive torque. However, the embodiment of FIG. 7 lacks this.

As a countermeasure against this, a drum-shaped pin 3 is installed inside the coil spring 25.
FIG. 8 shows a structure in which this defect is compensated for by providing 9.

Elastic deformation of the coil spring 25 is allowed by the size of the concave portion of the hourglass shape.

FIG. 9 shows a structure in which two driven shaft side flanges 33 of FIG. 7 are connected back to back to form a spacer 41, and is a spacer type shaft joint used for large pumps, compressors, etc.

Figures 10 and 11 show the reamer bolt 2 in Figure 2.
8 is provided to penetrate the center hole of the coil spring 25, and has a design that combines FIG. 2 and FIG. 7.

The drive shaft side bub 43 has the same structure as that shown in FIG.

In this case, the inner diameter of the coil spring 25 and the reamer bolt 4
Since there is some clearance around the outer periphery of 7, as shown in FIG. It must be fixed so that it does not rotate.

The reamer bolt 47 in this case is also as shown in FIG.
It is necessary to make it into an hourglass shape as shown in Fig. 8.

Above are explanatory diagrams of the coil spring installation positions, 4th, 5th,
In the 6th, 8th, and 11th drawings, the size of the clearance cyd shown in FIG. 2 is illustrated very large, but in reality, it is desirable that the force be smaller than the thickness of the rectangular cross section of the coil spring 25, and close to the actual size. An explanatory diagram of the shape is shown in FIG.

In this case, in order to allow the coil spring 25 to deform freely, the spring hole 50 of the drive shaft side bub 49 needs to be bored so as to expand into a trumpet shape toward the openings on both sides.

Further, if the thickness f of the wire of the coil spring 25 is larger than c or d, the coil spring 25 transmits torque by shearing force in response to excessive torque, so damage to the coil spring 25 can be minimized. As mentioned above, there is no need to insert a pin or reamer bolt into the center of the coil spring 25 to protect it.

The embodiments described so far are shaft couplings with a structure in which a holding cover is provided and thrust force due to compression of the coil spring is not applied to either the drive shaft side bubble or the driven shaft side bubble. If it is determined that there is no problem even if force is applied, there is a structure shown in FIG. 13.

The bubble 52 has the same shape on both the drive shaft side and the driven shaft side.

A sealing O-ring 53 is inserted between both the bubs 52.

In this case, a reamer bolt is not used, and the bolt 55 is used to compress the coil spring 25 via the holding plate 54.

It is the most compact and inexpensive compared to those shown in FIGS. 2 to 12.

In FIG. 14, by using a reamer bolt 56 instead of the bolt 55 in the tightening process shown in FIG. 13, the action of the thrust force can be somewhat reduced, but the compression of the coil spring 25 becomes somewhat unstable.

Finally, for intermediate shaft type shaft couplings, please refer to Figure 2 or 7.
The most common method is to connect the drive shaft side bubbles as shown in the figure with an intermediate shaft, but in order to reduce the vibration in the thrust direction of the intermediate shaft, the shaft coupling shown in Figure 13 is connected with an intermediate shaft 58. The one in FIG. 15 is optimal.

According to this method, the radial vibration of the intermediate shaft 58 is minimized due to the no-play effect of the coil spring 25, and the axial vibration is quickly damped by the thrust force due to the compression of the coil spring 25, and the axial vibration is As a swing shaft type shaft joint, it can perform extremely well.

As shown in the above embodiments, the present invention allows the installation of a wide variety of structures, and can provide equipment that meets the required specifications of each piece of equipment.

A shaft joint with no play is required for high-speed rotation, but the present invention not only has no play when new, but also
Even if some wear occurs in the reamed spring hole, play can be automatically eliminated by the elastic force of the coil spring.

There has never been a shaft coupling like this, especially for high-speed rotation transmission shaft systems, internal combustion engines, compressors, crank presses, etc.
The effects of the present invention are extremely significant in the drive system of machines that use crankshafts.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an example of a conventional shaft coupling using a coil spring, Fig. 2 is a cross-sectional side view of the shaft coupling showing an example of the present invention, and Fig. 3 is a shaft coupling shown in Fig. 2. A partially sectional front view of the joint, FIGS. 4 to 6 are explanatory diagrams of the shaft center adjustment of the shaft joint, FIG. 7 is a cross-sectional view showing another embodiment, and FIG. 8 is a main part of the shaft joint of the present invention. 9 and 10 are sectional views showing still other embodiments; FIGS. 11 and 12 are sectional views showing still other embodiments of the main part of the shaft coupling; 13 to 15 are sectional views showing still other embodiments of the present invention. 1.4, 9, 31. 33, 43, 52...bub, 2.7, 12.19...spring hole, 5.10.
...Bub cylindrical part, 6, 12, 34...Flange, 8゜13.20...Bolt hole, 16,
36, 45...Cover, 3,25...
Coil spring, 28, 38° 47.55, 56...
・Bolt, 54...Press plate, 58...
intermediate axis.

Claims (1)

[Claims] 1 each having a flange at one end of the cylindrical part, comprising a first bub and a second bub to which a transmission shaft is connected, and a plurality of holes are provided in the flange along the circumferential direction,
the flanges face each other at intervals, and the first
In a shaft joint in which a coil spring is inserted into the spring hole so that the bub and the second knob are disposed so as to span the flange, the coil is compressed by a bolt in the direction of the spring's axial force. A shaft coupling characterized in that the spring has an enlarged outer diameter and is tightly fitted into the spring hole.