Metal deforming – By use of tool acting during relative rotation between tool... – With tool surface orbiting around axis parallel to direction...
Reexamination Certificate
1997-11-03
2004-09-21
Larson, Lowell A. (Department: 3725)
Metal deforming
By use of tool acting during relative rotation between tool...
With tool surface orbiting around axis parallel to direction...
Reexamination Certificate
active
06792781
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for inclined rolling of tube-shaped or bar-shaped rolling products.
Arrangements for inclined rolling are mainly used for manufacture of seamless tubes, for example perforation of a round insert block and thereby for manufacture of relatively thick walled hollow block, or for stretching of such a hollow block with a reduction of its wall thickness or for expanding a tube loop. Moreover, it is known to use such arrangements for stretching and for cross-section reduction of bar-shaped or in other words massive rolling products.
In conventional arrangements of this type the rolling product is driven in rotation in two rollers which rotate in the same rotary direction and thereby is deformed. For obtaining a controllable displacement of the rolling product in the longitudinal direction the roller axes are arranged relative to the longitudinal axis of the rolling product with a pivoting angle. Therefore, from the peripheral speed of the rollers, a component in the longitudinal direction of the rolling product is produced and the rolling product is moved in a helical movement between the rollers in the longitudinal direction. Such arrangements have two or more driven rollers. Lateral guides between the rollers are needed when only two rollers are provided so that the rolling product remains in the region of the rolling axis does not spring out in a radial direction.
In such arrangements the barrel-shaped rollers are utilized with the roller axes extending parallel to the longitudinal axis of the rolling product. Moreover, it is known to use conical rollers in which the roller axes are inclined to the longitudinal axis of the rolling product. The inclination angle which is obtained here between the roller axes and the longitudinal axis of the rolling product should not be confused with the above mentioned pivoting angle, since the inclination angle alone without turning of the roller axes cannot provide an axial feed of the rolling product.
In the above mentioned arrangement the rolling product rotates about its longitudinal axis, which causes several problems. First of all rolling products of limited length only can be rolled, in order to avoid its unsteady rotary movement and to prevent damages to the rolling product and to the arrangement. -Secondly, expensive guiding devices for the rolling product and for eventually available inner tools are needed. Thirdly, the rolling product throughput and thereby the efficiency of the arrangement is narrowly limited. The rolling product throughput is determined by the feeding speed, and it is produced from the peripheral speed of the rolling product and the magnitude of the pivoting angle. Since the pivoting angle cannot exceed a predetermined magnitude because otherwise the surface of the rolling product becomes non-uniform and in particular wavy, the rolling product throughput is increased only by an increase in the peripheral speed. However, this increases the rotary speed of the rolling product as well which leads to an unsteady running resulting in damages to the rolling product, disturbances in the machinery and increased wear. Moreover, the rolling product during rolling must be accelerated stronger in view of the higher rotary speed of the rolling, which leads to sliding of the rollers and thereby to gripping problems. Fourthly, the rolling product which rotates about its longitudinal axis prevents a continuous finishing rolling in longitudinal rolling stands arranged at a short distance.
In view of the above disadvantages the kinematic principle of the inclined rolling was reversed. In particular it has been changed so that the rollers rotate not only around their roller axes, but also around the longitudinal axis of the rolling product. As a result the rolling product must not be brought to rotation about its longitudinal axis. The rollers roll in a planetary movement on and around the rolling product.
Such an arrangement is disclosed for example in U.S. Pat. No. 1,368,413. Here the rollers are supported with their roller shafts in a rotary housing which is driven through a toothed rim and a pinion. The shafts which drive the rollers has ends which face away from the rollers and are provided with toothed gears rolling on a sun gear as in a planetary transmission. The sun gear is also driven. With a corresponding determination of the rotary speeds of the rollers and the rotatable housing it is possible to roll the rollers on the rolling product without driving it in rotation. The rollers of this known type are barrel shaped and their roller axes extend in planes which are parallel to the longitudinal axis of the rolling product. The roller axes however are turned by an angle relative to the longitudinal axis of the rolling product in these planes, and thereby the feeding movement of the rolling product is produced. Also, the axes of the planetary gears extend with this angle relative to the longitudinal axis of the rolling product, but they are located in a plane which includes the longitudinal axis of the rolling product. The roller drive shafts between the planetary gears and the rollers are provided at their ends with joint couplings. In order to maintain the bending angle of the joint couplings not too great, the roller drive shafts are relatively long. This however leads to a long construction of the rotatable housing. Moreover, the long roller drive shafts are subjected during rotation of the rotatable housing to centrifugal forces and gyroscopic moments, which limits the rotary speed of the housing.
The German document DE-OS 16 02 153 shows in FIG. 1 an arrangement which in principle has the above described features. FIG. 2 however illustrates another construction. Here the rollers are conical and the roller axes extend under an inclination angle relative to the longitudinal axis of the rolling product. The rollers are supported floatingly in heads which are arranged at the end side of a rotor housing rotating around the longitudinal axis of the rolling product and driven through a toothed rim. The rollers are driven through several toothed gears or toothed gear drive steps arranged radially from the longitudinal axis of the rolling product one after the other. The first toothed gear engages a sun gear and rolls on it by the rotary movement of the rotor housing in which it is supported. In U.S. Pat. No. 1,368,413 the sun gear in this known construction is rotated by a special drive. The rotary speed of the sun gear and the rotary speed of the rotor housing can be selected so that the rollers roll on the rolling product without driving it in rotation. With the above mentioned inclination of the roller axes relative to the longitudinal axis of the rolling product no rolling product feed can be obtained. The feed is produced by a pivoting of the head which is arranged turnably around a bevel gear axis on the rotor housing. The pivoting angle produced in this manner is not shown in FIG. 2 of this reference. This construction has three rollers and is provided both for tube-shaped and for bar-shaped rolling products.
The latter construction is very expensive because of its roller drive. The toothed gears of the roller drive staggered radially outwardly from the longitudinal axis of the rolling product operates so that the rotating rotor housing has a huge outer diameter which, depending on the cross-sectional size of the rolling product, amounts to approximately 3-5 meter. The rollers, the roller shaft, their bearings and the head which has the drive gears are arranged on this big rotor housing, so that extraordinarily high rotating masses are produced in the case of great outer diameters. Because of the thusly generated centrifugal forces, the rotary speed of the rotor housing with the head is very limited and therefore the feeding speed of the rolling product is also limited. As a result, the throughput of the rolling product per time unit and therefore the efficiency is low. Since the head as well as the rotor housing have great sizes and there is a rel
Bindernagel Ali
Moeltner Herrmann
Kocks Technik GmbH & Co.
Larson Lowell A.
Striker Michael J.
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