JPH07132305A - Driving device of multistage cluster mill - Google Patents

Abstract

PURPOSE:To prevent the rotation unevenness of an output shaft, to reduce the fluctuation of a mill and to improve the rolling performance and the surface quality of a product. CONSTITUTION:A multistage cluster mill rotates an intermediate roll by engaging at least 2 teeth of output gears 15, 16 meshed with output shafts 13, 14 connected with an intermediate roll abutting on the work roll with an input gear 12 fitted to an input shaft 11 connected with a motor. The shaft diameter D of output shaft parts 13a, 14a of the central part to which each output gear 15, 16 is fitted is reduced in comparison with the shaft diameter D1 of other end parts 13b, 13c, 14b, 14c, the output gears 15, 16 and the output shaft end parts 13b, 14b are connected through couplings 17, 18, 26, 27 so that the torque transmitted to the output gears 15,16 is transmitted to the sides of the end parts 13b, 14b, of the output shafts 13, 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a multi-stage cluster rolling mill.

[0002]

2. Description of the Related Art A multi-stage cluster rolling mill of this type is, for example,
As shown in the roll arrangement in FIG.
Work rolls 1a and 1b, intermediate rolls 2a and 2b, and backup rolls 3a and 3b each having a small diameter are arranged in a cluster shape with four intermediate roll shafts 4a and 4a interposed therebetween.
4b is rotationally driven by the drive device 5 shown in FIGS.

Conventionally, this type of drive unit 5 is usually provided with two intermediate rolls 2 each of which is in contact with the work rolls 1a and 1b.
Since a and 2b are performed by one electric motor via a speed reducer, as shown in FIGS. 2 and 3, four output shafts 7a, 7a, 7b and 7b are provided for one input shaft 6. It is provided (for example, see Japanese Utility Model Publication No. 3-15209). And
The input gear 8 fitted to the input shaft 6 meshes with the output gears 9a and 9a fitted to the upper output shafts 7a and 7a, and the lower output shaft 7a is fitted to the output gears 7a and 7b. ，
Output gears 9b, 9b fitted in 7b are meshed with each other, and are connected to an input shaft 6 via a shaft coupling to an electric motor output shaft (not shown), and each output shaft 7a, 7b is connected to an output shaft (not shown). It is adapted to be connected to the intermediate roll shafts 4a and 4b via a universal joint, a spindle and the like.

Further, there is known a drive device provided with two output shafts for one input shaft so that each of the upper and lower intermediate rolls is driven by a separate electric motor (for example, Japanese Patent Laid-Open No. 59-59). (See No. 33015 and Japanese Utility Model Publication No. 3-15209) One of the two output shafts has an input gear engaged with the output gear, and the other output shaft transmits the input through a differential gear mechanism. Some of the above-mentioned methods are used (Japanese Patent Laid-Open No. 59-33).
015).

[0005]

By the way, in each of the above-mentioned prior arts, since the torque transmission from the input shaft is performed by the input gear and the output gear, even if the input shaft rotates smoothly with a constant angular velocity, Due to manufacturing error of gears, that is, pitch error and tooth shape error, the angular velocity of each output shaft does not become constant and some rotation unevenness occurs, and this rotation unevenness is transmitted to the intermediate roll as it is, causing vibration and rolling. There is a problem that chatter marks and the like are generated on the product surface, which deteriorates rolling performance and product quality.

The present invention has been made in view of the above situation, and an object of the present invention is to prevent uneven rotation of each output shaft to reduce vibration of a rolling mill, rolling performance, and rolling products. It is an object of the present invention to provide a driving device for a multi-stage cluster rolling mill capable of improving the surface quality.

[0007]

In order to achieve the above object, the present invention takes the following technical means. That is, according to the present invention, at least two output gears fitted to an output shaft connected to an intermediate roll in contact with a work roll are provided to an input gear fitted to an input shaft connected to a single drive source. By engaging the above, in the drive device of the multi-stage cluster rolling mill that rotationally drives the intermediate roll, the shaft diameter of the output shaft of the portion where each output gear is fitted is larger than the shaft diameter of the output shaft of the other portion. Is also reduced in diameter, and the torque transmitted to the output gear is transmitted to one end side of the output shaft.

[0008]

According to the present invention, when the output shaft advances faster than the constant rotation of the universal joint connected to the output shaft, a twist occurs in the reduced diameter portion of the output shaft to change the angular velocity of the universal joint. Can be minimized and the uneven rotation can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an essential part of an embodiment of the present invention, and the overall configuration of the driving device 10 is the same as that shown in FIGS. 2 and 3 in the axial arrangement of the input shaft and the output shaft. I will describe.

In FIG. 1, a drive unit 10 is an input shaft 11 connected to an electric motor (not shown) which is a single drive source.
Of the output gears 15 and 16 respectively fitted to the pair of upper and lower output shafts 13 and 14 connected to the intermediate roll contacting the work roll via the universal joint and the spindle. Outer output gear 1
5 and the upper and lower output gears 15 and 16 are meshed with each other.
The shaft diameter D of the central portion in which 16 is fitted, that is, the reduced diameter portions 13a, 14a is smaller than the shaft diameter D1 of the other end portions 13b, 13c, 14b, 14c, and the length L thereof is also made longer.

One end portion 13 of the output shafts 13 and 14
One of the gear couplings 1 is provided at the outer ends of b and 14b.
7, 18 are fitted, and the other end portions 13c, 14 of the output shaft
Sleeves 19 and 20 are externally fitted to c, and universal joints 21 and 22 are connected to the outer ends thereof. The output gears 15 and 16 have their boss portions 15a, 15b, 16a and 16b extending in the axial direction, respectively, and are fitted to the output shafts 13 and 14 so as to be rotatable relative to each other. 15b, 16a, 1
The outer ends of 6b are the output shaft both ends 13b, 13c, 1
4b, 14c, and each boss 15a,
15b, 16a and 16b are rotatably supported by the device casing 25 via bearings 23 and 24, respectively.

Couplings 26 and 27 are attached to the outer ends of the boss portions 15a and 16a of the output gears 15 and 16, respectively.
Are fixed by external fitting, and the flange portions 26a and 27a of the couplings 26 and 27 are attached to the gear couplings 17 and 18, respectively.
The torque transmitted to the output gears 15, 16 is connected to the output shafts 13, 14 via the couplings 26, 27, 17, 18 which are connected to the flange portions 17a, 18a of the bolts by bolts and nuts (not shown). Each is transmitted.

In the figure, 28 and 29 are bearing covers and 3
0 and 31 are spacers. Next, the operation of the above embodiment will be described. The torque from the drive source is the input shaft 11
Is transmitted to the output shafts 13 and 14 through the input gear 12, the output gears 15 and 16, and the couplings 26, 17, 27 and 18, and is transmitted to the intermediate roll shaft through the universal joints 21 and 22 and a spindle (not shown). Transmitted.

Therefore, the universal joints 21, 2
One end portion 13 of the output shafts 13 and 14 for a constant rotation of 2
b, 14b, that is, when the output gears 15, 16 travel fast,
Reduced diameter central portions 13a, 14a of the output shafts 13, 14
Twisting occurs and the universal joints 21 and 22 act so as to minimize the change in angular velocity. Therefore, uneven rotation of the output shafts 13 and 14 is eliminated.

The diameter reduction D in the above embodiment is determined by the following equation.

[0016]

[Number 1] ^{D = 3 √ (510T) (} mm) where, T is the transmitted torque (kgf · m), said transfer torque (output shaft average torque) T is calculated by equation (2).

[0017]

## EQU2 ## T = 974 × kw / n × 1/4 (kgf · m) where n is the number of revolutions and kw is the required power. Therefore,
When T is calculated with n = 710 and kw = 280, it is about 9
It will be 6 kgf · m.

From the relationship between the tooth profile error and the shaft rigidity, the output shaft torque fluctuation amount (ΔT) can be calculated by Equation 3.

[0019]

## EQU3 ## ΔT = π / 32D ⁴ × G × θ / L = π / 32 × 10 ^-3 × G × D ⁴ / L × sin ^-1 2e / PC
D where G is lateral elastic modulus (kgf / mm ² ) L is axial length (mm) e is tooth profile pitch error (mm) PCD is pitch circle diameter of output gears 15 and 16 (mm) θ is point A in FIG. 1 It is a change rad of the rotation angle of the shaft due to the tooth profile error in.

Therefore, when the transmission torque T is set to 96 kgf · m and the shaft diameter D is calculated from the above equations 1 and 2, it is 40 m.
m. The shaft diameter D is 40 mm, the pitch circle diameter PCD of the gear is 157 mm, the gear pitch error is 0.01,
0.03 and the shaft length L is 400 mm, the output shaft torque fluctuation amount (ΔT) and its ratio (ΔT / T) and the output shaft 13,
Table 1 shows the results of calculating the torsional stress (τ) (kgf / mm ² ) of No. 14.

The torsional stress (τ) of the shaft is calculated by the equation 4.

[0022]

## EQU4 ## τ = (16 × T) / (π × D ³ ) Also, in Table 1, the shaft diameter D in the conventional example is 70 mm and the shaft length L
Is 250 mm, which corresponds to D and L in FIG. 2, respectively.

[0023]

[Table 1]

Further, as a result of performing a rolling test on the examples 1 and 2 and the conventional examples 1 and 2 shown in Table 1 by the cluster rolling machine, chatter marks are generated on the product surface in the conventional example 1, and the driving device 5 and Vibration of the rolling mill is 1 to 4 mm / s,
Inferior products were observed, and in Conventional Example 2, thin chatter marks were sometimes generated on the product surface, which is not a problem as a product, but the vibration of the drive unit 5 and the rolling mill was about 1 mm / s.

On the contrary, in both Examples 1 and 2 of the present invention, the surface quality of the rolled product was extremely good without chatter marks and uneven gloss, and the vibration of the drive unit 10 and the rolling mill was minute. From the above, the torque fluctuation amount (ΔT) of the output shafts 13 and 14 is optimally set to 2 kgf · m or less, and in order to obtain the torque fluctuation amount, the rotation angle change of the shaft is changed according to each specification condition. , The gear grade and shaft length should be determined. It should be noted that the shaft diameter D of the output shafts 13 and 14 is naturally determined from the shaft strength in accordance with the above mathematical formula 1.

The present invention is not limited to the above-mentioned embodiment, but the design can be changed as appropriate, and for example, the upper intermediate roll and the lower intermediate roll can be configured to be driven by separate drive sources.

[0027]

As described above, according to the present invention, the input gear fitted to the input shaft connected to the single drive source is fitted to the output shaft connected to the intermediate roll contacting the work roll. In a drive unit of a multi-stage cluster rolling mill that rotationally drives the intermediate roll by meshing at least two output gears, the shaft diameter of the output shaft of the portion where each output gear is fitted is The diameter of the output shaft is smaller than that of the output shaft, and the torque transmitted to the output gear is transmitted to one end of the output shaft. It is possible to prevent uneven rotation of the rolls and realize smooth rotation with a constant angular velocity, improve rolling performance, reduce vibration of the rolling mill, and improve surface quality of rolled products.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a main part of an embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing a conventional example.

FIG. 3 is a left side view of FIG.

FIG. 4 is a roll layout diagram of a multi-stage cluster rolling mill.

[Explanation of symbols]

 1a, 1b Work roll 2a, 2b Intermediate roll 10 Driving device 11 Input shaft 12 Input gear 13, 14 Output shaft 13a, 14a Reduced diameter portion 13b, 14b One end portion 15, 16 Output gear D Shaft diameter D1 of reduced diameter portion Both ends Shaft diameter

Claims (1)

[Claims] 1. An input gear fitted to an input shaft connected to a single drive source, and at least two or more output gears fitted to an output shaft connected to an intermediate roll in contact with a work roll. In the driving device of the multi-stage cluster rolling mill that rotationally drives the intermediate roll by meshing, the shaft diameter of the output shaft of the portion where each output gear is fitted is larger than the shaft diameter of the output shaft of the other portion. A driving apparatus for a multi-stage cluster rolling mill, wherein the torque reduced in diameter and transmitted to an output gear is transmitted to one end of an output shaft.