JPH0117365Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a shaft coupling for connecting a large rolling roll for rolling steel or the like and a driving means for driving the rolling roll.

(Conventional example) Fig. 1 shows the connection between the end shaft of a large roll and the flange of a propeller shaft whose one end is connected to a drive source, where 1 is the shaft extended from the roll, and 2 is the shaft extending from the roll. The universal joint 3 of the propeller shaft is a flange connected to the shaft 1. in this way,
In order to rotate heavy objects such as rolling rolls, a drive shaft such as a slipper shaft or a hook-type universal joint shaft is generally used between the drive source and the
This drive shaft is also large in length and weight, and the load placed on the connecting portion is also very large.

For the connecting part between the shaft 1 and the flange 3, the cross-sectional shape of the shaft 1 is made into an oval shape as shown in Fig. 2, taking into consideration the magnitude of the load applied thereto, the amount of continuous use of the rolls, and economic efficiency. Generally, a prismatic key 4 is inserted between the shaft 1 and the flange 3. However, when this key 4 is subjected to a large load as described above, a large pressure is generated in the part that holds it, and this pressure is caused by various factors such as the inability to obtain a sufficiently large key size due to the roll diameter. constraints often result in load tolerance limits being exceeded, resulting in significant wear and sometimes deformation. As a result, the relative gap between the shaft 1, key 4, and flange 3 increases over time, and secondary shocks increase, resulting in poor rotational accuracy and the need for early repair or replacement. This often happens. in this way,
It is technically difficult to maintain the long life of shaft joints for heavy objects, and a solution to this problem has been a long-standing demand in the field.

(Purpose of the invention) In order to solve the above-mentioned drawbacks of the conventional example, the present invention uses a key made of a part of a cylinder whose central axis is offset from the central axis of the roll end axis. The present invention provides a shaft joint that reduces stress concentration when stress is applied and maintains smooth rotation. Hereinafter, embodiments will be described in detail with reference to the drawings.

(Example) Figure 3 shows an example of the present invention.
6 is a roll end shaft formed into an oval cross-sectional shape, and A is its central axis. 7 is a flange of the drive shaft, 8 is a key consisting of a part of a cylinder (herein referred to as a partial cylinder), and its cross-sectional shape is such that the part in contact with the shaft 6 is a straight line, and the part in contact with the flange 7 is
It consists of a circular arc centered at a point B that is different from the center A of the axis 1.

Now, when the flange 7 of the drive shaft rotates in the direction of arrow C, the rotational force is transmitted to the shaft 6 via the key 8. At this time, pressure is generated on the key 8 to transmit the load, and the force that causes the key 8 to rotate around B and move in the circumferential direction of the shaft 6 creates a gap between the shaft 6 and the key 8. As a result, the shaft 6 is self-centering, thereby suppressing the irregular movement caused by the occurrence of the gap as in the conventional example. Further, the arcuate outer circumferential surface of the key 8 reduces stress concentration that tends to occur in the flange 7, and reduces the decrease in mechanical strength of the flange. (In the conventional example shown in Figure 2,
The key corner of flange 3 is the weakest. ) FIG. 4 shows another embodiment of the present invention, in which the roll end shaft 11 and the flange 12
Four keys 13 and 14 are inserted between the shaft 11 and the keys 13 and 14, each of which is a partial cylinder having central axes E and F that are offset from the central axis D of the shaft 11. There is. Regarding the action when a rotational force in the direction of arrow G is applied to the flange 12,
This is the same as the case in FIG.

In addition, in the embodiment, the part where the rotational force is transmitted from the flange of the drive shaft to the roll end shaft has been explained, but when the rotational force is transmitted from the shaft of the drive source to the flange of the drive shaft, the part shown in FIG. In FIG. 4, the shafts 6 and 11 are the shafts of the drive source, and the direction of rotation thereof is as follows.
The arrows C and G are in the opposite direction with respect to the positional relationship of the keys. Further, the key is generally fixed to the flange by a bolt or the like that passes through the flange from outside the flange, but the bolt or the like is omitted from the drawing. Further, the surface of the key is subjected to so-called soft nitriding treatment or nylon coating treatment.

(Effects of the invention) As explained above, according to the invention, it is possible to reduce the increase in the relative gap between the shaft, key, and flange over time due to wear, and therefore, smooth transmission of rotational force is achieved over a long period of time. The life of the shaft joint can be significantly extended.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the connecting portion between the roll end shaft and the drive shaft, FIG. 2 is a cross-sectional view of a conventional example, FIG. 3 is a cross-sectional view of an embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view of another embodiment of the present invention. 6,11...Shaft, 7,12...Flange, 8,
13, 14...key.

Claims (1)

[Scope of utility model registration request] In a shaft joint that connects a rolling roll made of steel or the like and a driving means, a key inserted between a shaft and a flange is composed of a plurality of partial cylinders, and the cross-sectional shape of the partial cylinders is in contact with the shaft. A shaft joint characterized in that a portion thereof is a straight line, and a portion contacting the flange is an arc centered at a point different from the center of the shaft.